function isEqual(x, y) {
  if (x === y) {
    return true
  }
  if (!(x instanceof Object) || !(y instanceof Object)) {
    return false
  }
  if (x.constructor !== y.constructor) {
    return false
  }
  for (var p in x) {
    if (x.hasOwnProperty(p)) {
      if (!y.hasOwnProperty(p)) {
        return false
      }

      if (x[p] === y[p]) {
        continue
      }

      if (typeof x[p] !== 'object') {
        return false
      }

      if (!Object.equals(x[p], y[p])) {
        return false
      }
    }
  }
  for (p in y) {
    if (y.hasOwnProperty(p) && !x.hasOwnProperty(p)) {
      return false
    }
  }
  return true
}

module.exports = {
  isEqual,
}
